import java.util.Scanner;

/**
 * Created with IntelliJ IDEA.
 * Description:
 * User: Admin
 * Date: 2022-04-25
 * Time: 11:37
 */


class Animal {
    public String name;

    class Student {
        public int age;
    }
}
class Solution {
    public void merge(int A[], int m, int B[], int n) {

        int i = m-1;
        int j = n-1;
        int k = m+n-1;

        while(i>=0 && j>=0) {
            if(A[i] > B[j]) {
                A[k] = A[i];
                k--;
                i--;
            } else {
                A[k] = B[j];
                k--;
                j--;
            }
        }
        while(i >= 0) {
            A[k] = A[i];
            i--;
            k--;
        }
        while(j >= 0) {
            A[k] = B[j];
            k--;
            j--;
        }
    }
}
public class TestDemo {

    public static String fun(String str) {
        int array[] = new int[127];
        StringBuilder stringbuilder = new StringBuilder();
        for(int i = 0; i < str.length();i++ ) {
            char ch=str.charAt(i);
            if(array[ch] == 0) {
                stringbuilder.append(ch);
                array[ch] = 1;
            }
        }
        return stringbuilder.toString();
    }
    public static void main2(String[] args) {
        Scanner scan = new Scanner(System.in);
        while(scan.hasNextLine()) {
            String str = scan.nextLine();
            String str1 = fun(str);
            System.out.println(str1);
        }
    }


    public static void main1(String[] args) {
            Animal animal = new Animal();

            /*Student student = animal.new Student();
            Student student1 = new Animal().new Student();*/

    }
}